Embodiments of the present disclosure generally relate to an energy exchange assembly, and, more particularly, to systems and methods for forming spacer levels of a counter flow energy exchange assembly.
Energy exchange assemblies are used to transfer energy, such as sensible and/or latent energy, between fluid streams. For example, air-to-air energy recovery cores are used in heating, ventilation, and air conditioning (HVAC) applications to transfer heat (sensible energy) and moisture (latent energy) between two airstreams. A typical energy recovery core is configured to precondition outdoor air to a desired condition through the use of air that is exhausted out of the building. For example, outside air is channeled through the assembly in proximity to exhaust air. Energy between the supply and exhaust air streams is transferred therebetween. In the winter, for example, cool and dry outside air is warmed and humidified through energy transfer with the warm and moist exhaust air. As such, the sensible and latent energy of the outside air is increased, while the sensible and latent energy of the exhaust air is decreased. The assembly typically reduces post-conditioning of the supply air before it enters the building, thereby reducing overall energy use of the system.
Energy exchange assemblies such as air-to-air recovery cores may include one or more membranes through which heat and moisture are transferred between air streams. Each membrane may be separated from adjacent membranes using a spacer. Stacked membrane layers separated by spacers form channels that allow air streams to pass through the assembly. For example, outdoor air that is to be conditioned may enter one side of the device, while air used to condition the outdoor air (such as exhaust air or scavenger air) enters another side of the device. Heat and moisture are transferred between the two airstreams through the membrane layers. As such, conditioned supply air may be supplied to an enclosed structure, while exhaust air may be discharged to an outside environment, or returned elsewhere in the building.
In an energy recovery core, for example, the amount of heat transferred is generally determined by a temperature difference and convective heat transfer coefficient of the two air streams, as well as the material properties of the membrane. The amount of moisture transferred in the core is generally governed by a humidity difference and convective mass transfer coefficients of the two air streams, but also depends on the material properties of the membrane.
Air-to-air energy recovery cores are typically formed as cross-flow or counter-flow assemblies. At least some cross flow air-to-air energy cores are manufactured through modular components.
In contrast, counter flow energy recovery cores, which are typically able to transfer more energy as compared to cross flow configurations, are not as easily manufactured due to their size and complexity. Typically, counter flow energy recovery cores are manufactured as a large, single piece. As such, the cost of manufacturing a typical counter flow energy recovery core may be high, due to increased tooling costs and longer manufacturing times. Further, by manufacturing each spacer of a counter flow energy recover core as a single part, each produced energy recovery core typically requires its own tooling, thereby adding additional costs.
However, a known counter-flow energy recovery core is formed through two, large counter flow cores, each of which includes a plurality of air channel levels, and two cross flow cores, also each having a plurality of air channel levels, to form a single hexagonal counter flow core. However, the counter flow cores typically need a 45 degree manifold angle for the cross flow cores to fit thereto. Moreover, when two counter flow cores are connected together, a relatively large number of cross flow cores are needed to complete a hexagonal assembly. As an example, when connecting three counter flow cores together, six cross flow cores are typically used to complete the overall hexagonal assembly.
Thus, known methods for forming counter flow air-to-air energy cores are typically time and labor-intensive, as well as expensive.